Cerebral angiographic and clinical differences in carotid system transient ischemic attacks between American Caucasian and Japanese patients.

Cerebral angiographic findings of 32 Japanese patients with carotid system TIA's were compared with those of an equal number of age and sex matched American Caucasians. The end points included irregularity, ulceration, stenosis or occlusion of the carotid artery appropriate to the side of TIA. Atherosclerotic changes were found in 27 patients (84.4%) of the Japanese and 30 patients (93.7%) of the American patients. Mild lesions (49% stenosis and below) were similar in either frequency of topography between both groups; namely 25 intracranial and 17 extracranial lesions in Japanese as well as 29 intracranial and 10 extracranial in Caucasian patients. There was, however, an extra-intracranial difference in severe lesions (50% stenosis and above) between American Caucasian and Japanese patients; 10 of 12 severe lesions in Japanese were located intracranially, while 17 of 20 severe lesions present in the American group occurred in the extracranial portion of the internal or common carotid arteries.